Converting from a tank to tankless
Replacing a tank with a tankless unit is more than swapping boxes: the gas line, the venting and the water connections all change. Here is what the conversion involves, and when we would tell you to keep a tank.
What changes in a conversion
Tank versus tankless
- Gas supplyA tank burner is small; a tankless burner is large. The gas line to the heater is nearly always upsized.
- VentingA tank’s metal flue cannot be reused. Condensing tankless units vent in plastic pipe, usually straight out a nearby wall.
- Water connectionsNew supplies, isolation valves and often a small buffer or recirculation setup for homes with long runs.
- SpaceThe tank’s footprint becomes free floor space.
- Hot water behaviourNo more running out, but a second or two longer for hot water to arrive unless a recirculation line is added.
When a tank is still the right answer
If there is no practical vent route, if the gas meter cannot be upgraded, or if the budget this year only covers a like-for-like swap, a new tank heater is a sound choice and we will say so. A good tank installed well beats a tankless installed badly.
Electric-only homes and condos are a separate conversation: whole-house electric tankless rarely works in Seattle, so an electric tank, well installed, is usually the answer there.
How we approach it
We look at the gas, the vent route and the water during the free estimate and give you two written prices if it is a close call: tankless, and a new tank. You choose with the numbers in front of you.
Licensed, local, and on the record
- Licensed Bonded and insured in Washington
- Founder 15+ yrs in the plumbing trade
- Always Free estimates
- Available Same-day service
- Our promise 100% satisfaction guaranteed
Conversion questions
How long does a conversion take?
Usually one day, including removing the old tank. Gas meter upgrades, if needed, are arranged ahead with the utility.
Will I lose hot water pressure?
No. Flow is set by the unit’s sizing; a correctly sized tankless delivers full pressure to the fixtures it was designed for.
What happens to the old tank?
We haul it away and recycle it.
Talk to a Seattle plumber today
Tell us what is happening and we will give you a free, written estimate. Same-day service is available for most calls. No pressure, no obligation.
Serving Seattle, Shoreline, Bellevue and Mercer Island.